JPS6215752B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-contact engine ignition system that can control engine ignition timing to desired characteristics.

Conventionally, this type of engine ignition system controls the primary current of the ignition coil by operating a switching element such as a thyristor or transistor using an ignition signal generated at the ignition timing synchronized with the rotation of the engine to ignite the secondary side. Generates voltage. In this case, the ignition signal voltage generated in the signal generator coil synchronized with the rotation of the engine is directly supplied to the switching element as an ignition signal, so the ignition timing advance characteristic is determined by the output waveform of the ignition signal. The disadvantage was that it could not meet the advance angle characteristics required for

In view of the above drawbacks, the present invention provides a non-contact type engine ignition system that arbitrarily controls the advance characteristics of engine ignition timing to satisfy the advance characteristics required by the engine.

The embodiment shown in FIG. 1 will be described below.
In FIG. 1, reference numeral 1 denotes a generator coil that is built in an AC magnet generator driven by an engine (not shown) and generates an AC output voltage in synchronization with the rotational speed of the engine;
2 is a diode that rectifies the alternating current output of the generator coil 1; 3 is a capacitor that is charged by this rectified output; 4 is an ignition coil; 5 is a spark plug; 6 is a thyristor that is a semiconductor switching element; A discharge circuit is configured to discharge the accumulated charge to the primary coil of the ignition coil 4. 7 is the ignition coil 4 due to the electric charge charged in the capacitor 3.
A diode 8, which bypasses the electromotive force generated in the spark plug 5 and causes the spark plug 5 to perform DC discharge, is an advance characteristic control circuit that constitutes a main part of the present invention. 9 is a first signal generator that is driven by the engine and generates an output voltage at a certain ignition angle position set in synchronization with the rotation of the engine; 10 is a diode that rectifies the output of this signal generator 9; 11 is a diode that rectifies the output of the signal generator 9; The capacitor 12 charged by the rectified output of the diode 10 is a thyristor which is a semiconductor switching element for determining ignition timing.The anode of the thyristor 12 is connected to the capacitor 11, and the cathode is connected to the gate of the thyristor 6. Capacitor 1 on the gate of 6
This constitutes a discharge path for discharging one charge. 13
is a second signal generator that is driven by the engine and generates an AC output voltage whose value increases and decreases as the engine speed increases and decreases; this signal generator 13 and the first signal generator 9 are connected to the above-mentioned AC magnet. attached to the generator. Reference numeral 14 denotes a diode that supplies one wave of the AC output of the second signal generator 13 to the gate of the thyristor 12 as an ignition signal, and this gate circuit is a closed circuit completely independent of other circuits.

Next, the operation of the device configured as described above will be explained with reference to the operational waveform diagram in FIG. 2 and the advance angle characteristic curve diagram in FIG. 3.

Here, in FIG. 2, A indicates the output voltage v ₁ of the first signal generator 9, B indicates the charging voltage vc between the terminals of the capacitor 11, and C indicates the second signal generator 13.
D indicates the trigger timing and conduction period of the thyristor 12, E indicates the trigger voltage vg of the thyristor 6 _, and vt indicates the trigger level of the thyristor 12. The first signal generator 9 generates a short period pulse-like output voltage v ₁ at an angular position corresponding to the maximum advance angle of the engine ignition timing, and the second signal generator 13 generates a short period pulse-like output voltage v 1 at an angular position corresponding to the maximum advance angle of the engine ignition timing. The output voltage v ₂ is configured to generate an output voltage v ₂ with a wider period including this period than the short period of the above-mentioned output voltage v 1 in order to correspond to this period.

Figure 3 shows the conventional advance angle characteristic diagram,
is a lead angle characteristic diagram obtained by an example of the present invention.

First, a magnet generator is driven by the rotation of the engine, and the AC output generated in the generator coil 1 is rectified by the diode 2 to charge the capacitor 3. On the other hand, the output voltage v ₁ generated in the first signal generator 9
is rectified by diode 10 and connected to capacitor 1
Charge 1. Then, the engine ignition timing becomes the second
When the output voltage _v2 generated in the signal generator 13 reaches the trigger level vt, it is supplied to the gate of the thyristor 12 via the diode 14, so that the thyristor 1
2 becomes conductive, and the charge VC of the capacitor 11 is supplied to the gate of the thyristor 6. Then, the thyristor 6 becomes conductive and the charge in the capacitor 3 is discharged to the primary coil of the ignition coil 4, so an ignition voltage is generated in the secondary coil, and in response to this ignition voltage, a spark discharge is generated in the ignition plug 5. It will be done.

Here, to explain in detail the advance angle operation by the advance angle control circuit 8, the output voltage V ₁ generated in the first signal generator 9 is rectified via the diode 10 and charges the capacitor 11.
1 is the output voltage of the first signal generator 9 V ₁
Also, for the convenience of explaining the operation, the range of engine rotation speeds is defined as low rotation speed n ₁ , medium rotation speed n ₂ , and high rotation speed n _3.
(n ₁ < n ₂ < n ₃ ).

The current engine speed n is from low rotation speed n ₁ to medium rotation speed n ₂
In the rising rotation speed range up to, the second signal generator 1
The AC output voltage v ₂ of No. 3 also increases as the rotation increases. Therefore, the trigger level of thyristor 12 vt
is constant, so if the AC output voltage v ₂ increases, the angular position θ at which the AC output voltage v ₂ reaches the trigger level vt becomes earlier (advanced) as the rotation speed increases, so the thyristor 12 starts conducting. The period is from θ ₁ to θ
You can proceed to ₂ . Therefore, the timing at which the trigger voltage vg is supplied to the gate of the thyristor 6 changes from θ ₁ to θ ₂ . That is, as the engine speed n increases, the ignition timing advances from θ ₁ to θ ₂ as shown in FIG. Next, the engine speed n is medium rotation speed n ₂
As the rotational speed increases further from _n3 to a high rotational speed n3, the AC output voltage _v2 of the second signal generator 13 also increases further, so that the angular position θ that reaches the trigger level vt of the thyristor 12 is brought forward, and the rotational speed of the thyristor 12 is accelerated. The timing at which conduction starts is θ ₃ as shown in FIG. Therefore, when the engine speed n becomes higher than the high speed _n3 , the output voltage _v2 of the second signal generator 13 also increases, and the timing at which the thyristor 12 starts conducting is brought forward to _θ4 . However, at this time, the output voltage _v1 of the first signal generator 9 has not yet been generated, and the capacitor 11 has not stored the charging charge vc, so the timing at which the conduction of the thyristor 12 starts is not advanced and θ It's time for ₃ .

That is, when the engine rotational speed n becomes higher than the high rotational speed _n3 , the thyristor 12 maintains a conductive state by the output voltage _v2 of the second signal generator 13, and the angle of _θ3 When the position is reached, the output voltage v ₁ generated in the first signal generator 9 is applied as a trigger voltage vg to the gate of the thyristor 6 through the thyristor 12, and the thyristor 6 becomes conductive. Therefore, the ignition timing of the engine is maintained at θ ₃ shown in FIG. 3 and is not advanced any further.

As mentioned above, in this embodiment, the advance angle θ
The engine speed n corresponding to ₃ is the rotation range up to ₃ .
The output voltage v ₁ of the signal generator 9 is temporarily stored in the capacitor 11, and the timing at which the thyristor 12 starts conducting is determined by the output voltage v ₂ of the second signal generator 13, which increases as the engine speed n increases. By early supplying the charged charge vc of the capacitor 11 to the thyristor 6 through this thyristor 12 and making it conductive, the engine speed n responds to the rise from the low speed _n1 to the medium speed _n2 and then to the high speed _n3 . Then, the ignition timing θ is θ ₁ ,
The angle is automatically advanced to θ ₂ and θ ₃ . Then, when the engine speed n becomes higher than the high speed _n3 , the output voltage _n2 of the second signal generator 13 maintains the thyristor 12 in a conductive state before the output voltage _v1 of the first signal generator 9 is generated. Since the thyristor 6 is made conductive by the output voltage v ₁ generated in the first signal generator 9 at a certain time, the advance angle is up to θ ₃ , and there is no advance beyond this point. Maximum advance angle.

Incidentally, according to this embodiment, it is also possible to obtain the advance angle/retard angle characteristic curve shown in FIG. 4. That is, in the case of generating electricity using a magnet generator, the influence of armature reaction is noticeable, and therefore the output voltage _v2 of the second signal generator 13 in the embodiment of FIG. 1 also has a high rotation speed. 4, the output voltage v ₂ exhibits a characteristic of falling as shown in FIG. 4.

By utilizing this characteristic, the engine ignition timing θ can be sequentially retarded as the engine speed n increases from the maximum advance state at the engine speed _n5 .

FIG. 5 shows a second embodiment of the signal control circuit 8, in which a third signal generator 15 that generates the output voltage _v3 with a steep rise shown in FIG. 12 gates are connected between the cathodes. That is, the second signal generator 13
are connected in parallel. E in Fig. 6 is the combined output voltage of the second and third signal generators 13 and 15.
Indicates v ₄ .

To explain the operation with reference to the operating waveform diagram in FIG. 6 and the advance angle characteristic curve diagram in FIG. 7, _first , the second signal generator 1
The output voltage _v2 of the third signal generator 15 has not yet reached the voltage value that reaches the trigger voltage vt, while the steep output voltage _v4 of the third signal generator 15 has reached the trigger voltage vt even at a rotation speed that allows the engine to start. . Therefore, the steep output voltage of the third signal generator 15 is applied to the gate of the thyristor 12.
A composite voltage v ₄ of v ₃ and the output voltage v ₂ of the second signal generator 13 is applied, and as a result, the thyristor 12 is made conductive by the steep output voltage v ₃ of the third signal generator 15. Due to this conduction, the charge vc of the capacitor 11 is supplied to the thyristor 6 through the thyristor 12, and its conduction starts at θ ₁ , which means that the output voltage v ₂ of the second signal generator 13 is at the trigger level.
Continues until vt is reached. That is, engine speed n
Until n ₁ , the thyristor 12 starts conducting at the third
It is determined by the steep output voltage v ₄ of the signal generator 15 and continues to remain constant. The subsequent operations are the same as those in the embodiment shown in FIG. 1, and will therefore be omitted. Even in this embodiment, it is possible to add the retardation characteristic shown in FIG. 4.

Note that the present invention is applicable not only to CDI ignition but also to other ignition devices such as AC ignition. Further, the thyristor 12 may be a general switching means such as a transistor, and it is also possible to obtain both zero advance angle and advance angle characteristics as advance angle characteristics.

As described above, in this invention, firstly, both the advance angle characteristic and the maximum advance angle characteristic can be obtained electrically, and secondly, the three advance angle characteristics, the zero advance angle characteristic, the advance angle characteristic, and the maximum advance angle characteristic can be obtained electrically. The obtained product is excellent in practical use because it can meet the advance angle characteristics required by the engine.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram showing one embodiment of the present invention, Fig. 2 is its operating waveform diagram, Fig. 3 is a lead angle characteristic curve diagram, Fig. 4 is another lead angle characteristic curve diagram, and Fig. 5 6 is an electric circuit diagram showing an embodiment of the second invention, FIG. 6 is an operating waveform diagram thereof, and FIG. 7 is a lead angle characteristic curve diagram. In the figure, 1 is the generator coil, 2, 7, 10, 1
4 and 16 are diodes, 3 and 11 are capacitors,
4 is an ignition coil, 5 is a spark plug, 6 and 12 are thyristors, 8 is an advance control circuit, 9 is a first signal generator, 13 is a second signal generator, and 15 is a third signal generator. Note that the same reference numerals in each figure indicate the same parts.

Claims (1)

[Claims] 1. In a device that generates an ignition voltage by controlling the primary current of an ignition coil by an ignition semiconductor switching element, the ignition voltage is generated in synchronization with the rotation of the engine and at the maximum advance position of the engine. A first ignition signal generating means generates a pulsed output voltage with a relatively narrow width, and when the engine is ignited at an ignition position until the maximum advance position of the engine is reached, the first ignition signal generating means charges the engine. a capacitor that discharges a charged charge at the ignition timing of the engine; a semiconductor switching element for determining the ignition timing that is connected to the capacitor and the semiconductor switching element for ignition and drives the semiconductor switching element for ignition; and a semiconductor switching element for determining the ignition timing; provided in the control circuit of the semiconductor switching element for the engine, whose peak value increases and decreases as the rotational speed of the engine increases and decreases, and includes a period during which the pulse-shaped output voltage is generated by the first ignition signal generating means, and the pulse-shaped output A second ignition signal generation means generates an output voltage having a waveform width wider than the voltage, and the maximum advance position of the engine is determined by the first ignition signal generation means until the maximum advance position is reached. A non-contact type engine ignition system, each of which is determined by the output voltage of the second ignition signal generating means. 2. The contactless engine ignition system according to claim 1, wherein the control circuit for the semiconductor switching element for ignition timing determination including the second ignition signal generating means is an independent closed circuit. 3 In devices that generate ignition voltage by controlling the primary current of the ignition coil by an ignition semiconductor switching element, a relatively narrow pulse pulse is generated in synchronization with engine rotation and at the maximum advance position of the engine. When the engine is ignited at the ignition position until the maximum advance position of the engine is reached, the first ignition signal generating means generates an output voltage of A capacitor that discharges a charged charge at the timing, a semiconductor switching element for determining ignition timing that is connected to the capacitor and the semiconductor switching element for ignition, and that drives the semiconductor switching element for ignition, and control of the semiconductor switching element for determining the ignition timing. a waveform width that is provided in the circuit, whose peak value increases or decreases as the rotational speed of the engine increases or decreases, and which includes a generation period of the pulsed output voltage by the first ignition signal generating means and is wider than the pulsed output voltage; a second ignition signal generating means for generating an output voltage having an output voltage of
A second signal generating means generates an output voltage that is steeper than the output voltage near the maximum value of the output voltage, and is combined with the output voltage of the second signal generating means to drive the ignition timing determining semiconductor switching element. Non-contact type engine ignition system equipped with 3 ignition signal generation means.